Onion weed control in medic pastures - a herbicide evaluation

2015
CC BY 4.0

Research organisatons
Funding source

Trial details

Researcher(s) Brian Dzoma (EPARF)
Year(s) 2015
Contributor Eyre Peninsula Agricultural Research Foundation
Trial location(s) Kyancutta, SA
Onion weed control in medic pastures - a herbicide evaluation locations
Aims

Onion weed (Asphodelus fistulosusis) is a significant pest of crops and pastures on many soil types on upper EP. Onion weed that germinates in the pasture phase often results in thick stands of large plants that require repeated herbicide application and/or cultivation to control prior to a crop phase. Cultivation prior to sowing is a widespread practice to control the weed and reduce the residues to manageable levels. However, cultivation can expose the soil to erosion.

Onion weed in pastures regularly sets seed prior to the end of the growing season, ensuring the seed bank is replenished and the weed persists in every phase of the rotation. A key strategy to reduce the impact of onion weed, and the need for cultivation, is to reduce growth and seed set in the pasture phase of the rotation. Non-selective herbicides can control actively growing onion weed plants, but pasture growth is also affected.

Previous trials by the UNFS group, MDB NRM, and PIRSA have shown the following herbicides can provide adequate control of onion weed in non-selective situations:

                    Paraquat and double knocks of paraquat

                    Glyphosate plus metsulfuron methyl mixtures (+/- paraquat second knock)

                    Glyphosate plus LVE ester 2,4- D plus metsulfuron methyl,( +/- paraquat second knock)

                    Chlorsulfuron

                    Spray Seed

                    Alliance

 

This trial was established to investigate herbicide control of autumn/winter germinating onion weed in the pasture phase, while maintaining the productivity of the medic pasture. This trial evaluated the herbicide control of young actively growing onion weed in a vigorous medic pasture. The herbicides, with the exception of paraquat, were chosen to minimise the impact on the medic biomass production.

Key messages
  • Onion weed is a significant pest and competitor of medic pastures. In mixed farming systems, control in the pasture phase is often reliant on cultivation.
  • None of the herbicides evaluated in this trial provided adequate onion weed control in the medic pasture phase without unacceptable reduction in medic biomass.
  • The use of non-selective herbicides and their mixes, combined with strategic cultivation if required, is still the most effective short term strategy in reducing the impact of onion weed on crop/pasture systems on Eyre Peninsula (EP).
Lead research organisation SARDI Minnipa Agricultural Centre
Host research organisation Eyre Peninsula Agricultural Research Foundation
Trial funding source NLP
Related program N/A
Acknowledgments

Thanks to Tash and Brett O’Brien for the use of their property. This trial was funded by the EPNRM Board through the National Landcare Program. Trial Products were supplied by Bayer Crop Science (Brodal Options), Nufarm (MCPA Agritone 750ai, Kyte 700 WG, BroadSword, Buttress, Bromicide 200), Crop Care (Alliance, Agtryne MA, Nail 240, Raptor WG), Syngenta (Gramoxone 250), Sipcam (Ecopar).


Other trial partners Eyre Peninsula Natural Resources Management Board
Download the trial report to view additional trial information

Method

Crop type Pasture: Medic
Treatment type(s)
  • Herbicide: Type
Trial type Experimental
Trial design Replicated

Kyancutta 2015

Sow date Not specified
Harvest date Not specified
Plot size 6m x 1.5m
Plot replication 3
Herbicide

Herbicide treatments were applied to the replicated trial on 29 May 2015 with a tractor mounted 3-point linkage shrouded sprayer (water rate @ 100 L/ha). Most of the onion weed was less than 10 cm high. Onion weed counts were taken from each plot prior to herbicide application and at the end of the trial.

See article for herbicide used and rates.

Download the trial report to view additional method/treatment information
Trial source data and summary not available
Check the trial report PDF for trial results.
Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Kyancutta, SA Sandy loam
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Kyancutta, SA Tenosol
Soil Moisture Source: BOM/ANU
Average amount of water stored in the soil profile during the year, estimated by the OzWALD model-data fusion system.
Year Kyancutta SA
2015 157.9mm
2014 191.3mm
2013 155.4mm
2012 171.2mm
2011 192.7mm
2010 183.5mm
2009 201.3mm
2008 155.5mm
2007 154.2mm
2006 172.3mm
2005 166.7mm
2004 152.6mm
2003 157.2mm
2002 159.9mm
2001 189.8mm
2000 200.1mm
National soil grid Source: CSIRO/TERN
NOTE: National Soil Grid data is aggregated information for background information on the wider area
Actual soil values can vary significantly in a small area and the trial soil tests are the most relevant data where available

Soil properties

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Climate

Kyancutta SA 2015


Observed climate information

Rainfall avg ann (mm) 316mm
Rainfall avg gsr (mm) 248mm
Rainfall trial total (mm) 278mm
Rainfall trial gsr (mm) 253mm

Derived climate information

Kyancutta SA

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Some data on this site is sourced from the Bureau of Meteorology

SILO weather estimates sourced from https://www.longpaddock.qld.gov.au/silo/
Jeffrey, S.J., Carter, J.O., Moodie, K.B. and Beswick, A.R. (2001). Using spatial interpolation to construct a comprehensive archive of Australian climate data , Environmental Modelling and Software, Vol 16/4, pp 309-330. DOI: 10.1016/S1364-8152(01)00008-1.

Trial report and links

2015 trial report



Trial last modified: 04-06-2019 14:59pm AEST